Expansion of antigen-specific T cells is complicated by the rarity of antigen-specific naive precursors, which can be as few as one per million. To generate the large numbers of tumor-specific T cells (for example) required for adoptive therapy, lymphocytes are conventionally stimulated with antigen over many weeks, often followed by T cell selection and sub-cloning in a labor intensive process.
There is a need for technologies that can quickly generate large numbers and high frequencies of antigen-specific T cells from naive precursors, or quickly identify T cell responses to candidate peptide antigens, for both therapeutic and diagnostic purposes.